My first thought was to change the 3.5mm cable to Kimber or Van der Hul, and the power supply to 10,000uF.

Then my thoughts went to the enclosure. Now the Concerto had a cardboard tube, abeit somewhat thicker than a pringles can.
1 How do I line inside a cylinder with bitumen pads?
2 Maybe cross bracing with plywood on resilisnt rubber pads a la LS50?
3 Damping, perhaps 3 layer, hard foam, rock wool then cotton wool.
4 Finite Element Analysis showed that the enclosure was a cylinder!
5 Linkwitz Pluto uses a cylinder so I'm on to a good thing since it's almost as good as an Orion.
6 Maybe I need Computational Fluid Dynamics on the tube? Cut it in half and join with some large radiator hose for a flexible turbulence reducing middle?
7 Glue ceramic tiles on outside of tube? or encase the whole thing in a solid block of concrete?
8 Concrete base and stand? - umm... not very practical with my mp3 player
9 But the dispersion and lack of diffraction of this design is going to be wonderful
10 Replace the driver with a Falcon B110, add a tweeter in a plywood thin wall rectangular box and drive it with a Krell....

You should know by now not to tamper with the original design. The speaker and Pringles can must be treated as a complete system. Goodness knows what could happen. Although a concrete base could stop it falling over I suppose....

As an old, experienced hand at this, I must inform you that it sounds better after you eat the contents. I've been eating the contents for many years.

This is a free tip! No need to thank me! _________________Sometimes I lie awake at night, and I ask, "Where have I gone wrong?" Then a voice says to me, "This is going to take more than one night."
-- Charles M. Schulz (as Charlie Brown)